1. Field of the Invention
The invention is directed to an adjustable plate mold with narrow-side walls which can be clamped between broad-side walls and which are articulated in each instance in the upper and in the lower outwardly directed edge area of the narrow-side walls at an actuating drive inserted in a cassette holder.
2. Description of the Related Art
A process for changing a strand cross section format and a mold for carrying out the process are known from German reference No. DE-OS 29 23 113, wherein actuating drives mounted in a frame surrounding the side walls of the mold are articulated at the narrow-side walls. The actuating drives can be actuated independently from one another and at least one actuating drive is mounted at the frame in an articulated manner, i.e., so as to permit a swiveling movement in the plane of symmetry parallel to the broad-side walls.
Adjusting devices for molds constructed in this way have the disadvantage that the adjusting device must absorb shearing forces at least outside of the clamping phase of the narrow-side walls by the broad-side wallsxe2x80x94i.e., when the narrow-side walls are not clamped by the broad-side walls.
A further disadvantage of this device is that the narrow-side walls are lifted out of the broad-side walls by a rocking or swaying motion of the narrow-side walls. During this type of swaying motion of the narrow sides in the known device, the narrow side describes a circular path about the center of rotation of the narrow-side drive during the straight-line guidance stage of the slab being formed.
Also known in practice are narrow-side walls which are movable on a horizontal path by a type of tongue-and-groove guide. This type of guide is disadvantageous because the guides are exposed to a high degree of contamination during the harsh steelmaking operation and because of the related high maintenance costs.
It is an object of the present invention to overcome the problems of the prior art and to provide an adjustable plate mold having narrow-side walls between broad-side walls in which a horizontal position of the narrow-side walls is adjustable to a predetermined position during a change in the slab format in a simple manner, without obstruction and with low maintenance.
This object of the present invention is achieved by an adjustable plate mold for forming a slab having a cross-section of predetermined length and width, comprising sidewalls defining a length and a width of the slab to be formed including a pair of opposing broad-side walls and first and second narrow-side walls clampable between the broad-side walls, and a framework including first and second cassette holders respectively corresponding to the first and second narrow-side walls, first and second actuating devices respectively inserted in the first and second cassette holders and connected to the first and second narrow-side walls, the first and second actuating devices operatively arranged for respectively moving the first and second narrow-side walls along a horizontal line for adjusting a size of the slab to be output, and first and second holding parts respectively connected between the first and second cassette holders and the first and second narrow-side walls for holding the first and second narrow-side walls at a constant horizontal level along the horizontal line.
According to the invention, holding parts are provided which hold the narrow-side walls on a predefinable horizontal line. These holding parts, together with the actuating drives and the narrow-side walls and cassette holders, form a framework. This particularly rigid construction prevents any swaying movement of the narrow-side walls. At the same time, the desired position of the narrow-side walls is exactly maintained, especially when the narrow-side walls are not clamped by the broad-side wallsxe2x80x94i.e., outside of the clamping phase of the narrow-side walls by the broad-side walls.
In one embodiment, the holding part is a rod guided at an angle to the respective narrow-side wall and adjustable in length. The other end of the rod may be fastened to a cassette holder which supports the actuating device for the respective narrow-side wall and is guided diagonal to the frame formed of the actuating drives, narrow-side walls and cassette holders. Two diagonal rods which are constructed as piston-cylinder units or electric linear drives are preferably provided.
In another embodiment, the rod has a thread that corresponds with a spindle nut which is fastened to the cassette holder. This rod is dimensioned such that it can reliably assume the anticipated tensile and compressive forces. The movement of the adjusting drives is carried over to the spindle nut in a corresponding manner and the length of the diagonal rod of the framework is correspondingly changed.
In another embodiment, the holding part is a rope connected with a drivable rope drum arranged at the cassette holder. Since the rope can only receive tensile forces, a second rope is installed insofar as the holding part must also absorb compressive forces, wherein this second rope is arranged symmetric to the first holding part with respect to tilt and, through the reversal, takes over the compressive forces.
In yet another embodiment, the holding part is a simple rod which is connected to a two-arm lever. A first arm of the two-arm lever connected to the rod is so dimensioned that it supports negligibly small bending forces, so that the rod forms a complete framework with the narrow-side walls and the actuating drive.
A measuring and regulating device is suitably connected with the actuating drives on the one hand and with the drives of the holding part for providing reliable adjustment of the narrow-side walls.
The various features of novelty which characterize the invention are pointed out with particularity in the claims annexed to and forming a part of the disclosure. For a better understanding of the invention, its operating advantages, and specific objects attained by its use, reference should be had to the drawing and descriptive matter in which there are illustrated and described preferred embodiments of the invention.